Actually, I'm going to re-open this in case someone would like to fix it since I believe it is a bug. It can be closed once newforms is actually getting used for the generic views. It seems possible that a flatten_data() could be added to the Manipulator class, but it could not just be the version from the AutomaticManipulator class since that accesses attributes only available for AutomaticManipulator instances. Perhaps it just needs to call flatten_data on each field.

If you would like to see this, then please submit a patch and tests.

I have added this as a Manipulator ticket to track on the FeatureGrouping page.

Aah .. only after the fact do I realise that Gary's comment #4 could be interpreted not as a code change but an alternative, also valid, approach to the problem.

Not to worry too much, since this is advanced and not overly common usage (if you're using custom manipulators in conjunction with generic views, you presumably have enough programming experience to realise there are alternatives) for a feature with limited life expectancy. What we've got now should work.